if ( window['Openjsl'] && !Openjsl['core'] ) {
    Openjsl['core'] = true;

    /**
     * Смена текущего контекста
     */
    function ojsl_ctx_activate( canvas_obj ) {
        Openjsl.core['active_ctx'] = canvas_obj.getContext( '2d' );
    }

    alert( 'Core loaded!' );
}
